What will the speed of sound be at 40 °C?

Think it through first, then pick an option.

a 332 m s⁻¹
b 350 m s⁻¹
c 353 m s⁻¹
d 362 m s⁻¹

Answer and explanation

Correct answer: c 353 m s⁻¹

The stem gives no speed at 0 °C, so take the listed 330 m/s: v = 330 × √(313/273) = 353.3 m/s ≈ 353. With 332 it would be 355.5, which is not offered.

Why the other options are wrong

a 332 m s⁻¹: 332 m/s is the speed at 0 °C in exercise values. At 40 °C the air is much warmer, so the speed is higher than that.
b 350 m s⁻¹: 350 is about the speed at 30 °C (349.8). At 40 °C, T = 273 + 40 = 313 K, so the speed is higher still.
d 362 m s⁻¹: 362 needs about 32 added to 330. But the speed grows as √T, not in a straight line; from 0 to 40 °C it rises by only about 23 m/s.